The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
In modern times the rapid pace of life, high-pressure work, and irregular meal patterns adversely affect our bodies. Hence, health examinations, such as blood tests, eye examinations, and balance evaluations, become particularly important. Health examinations can also provide warnings when there are signs detected from our bodies which promotes early treatment and improved the effectiveness of health maintenance.
In the past, balance scale or functional tests, such as Berg Balance Scale and Timed Up and Go Test, were commonly used in clinics to determine a patient's balance ability. The Berg Balance Scale was developed by Katherine Berg and her colleagues early in 1989 to evaluate the functional static and dynamic balance abilities. In 1992 and 1995, the Berg Balance Scale was increasingly applied for the elderly and acute stroke patients. Research results showed excellent within-rater, between-rater reliabilities (both ICCs were 0.98) and internal consistency (Cronbach's α=0.96). In 1996, Bogle and other researchers used this balance scale to assess balance status and fall risk among elder people. They found that those who scored less than 45 points had a higher chance of falls compared to those who scored more than 45 points. Although it didn't mean that the lower a subject scores the higher chance of falling the subject has, it still provides a cut-off point (cut-off score) to predict the possibility of falls in clinical practice. The Timed Up and Go Test was first used by Mathias and the colleagues in 1986 to study 40 elder people exhibiting balance dysfunctions. They observed the subject rising from a chair with handles, walking three meters, turning around, walking back to the chair, and sitting down. This test integrates a series of daily of activities such as from sitting to standing, walking, turning, and from standing to sitting. Although this test is a fast and useful balance function test, the scoring procedure is rough and balance function is scored on a five-point scale. Only extreme scores of 1 and 5 are scored with a more consistent consensus, while intermediate scores of 2 to 4 are less objective.
Due to the development of technology and medicine, members of society are aging in recent years. Some manual health examinations, such as eye examinations and balance evaluations, have been replaced by instruments. For instance, due to the invention of the electronic force plate, the measurement of position of center of gravity becomes more accurate. The principle of the force plate is to use uniaxial piezoelectric pressure sensors or triaxial piezoelectric pressure sensors to detect pressure signals from different directions, and convert the signals into the distribution of the position of center of gravity.
Taiwan Patent No. M404973 “THE NEW THREE-DIMENSIONAL FORCE PLATE” discloses a three-dimensional center-of-gravity position measuring force plate, including a balance board, four columns, a base plate, and four groups of pressure sensing modules that are composed of different specifications of pressure sensors, to achieve accuracy of measurement. The columns are disposed on the base plate and the groups of pressure sensors orthogonally contact the top of the columns. When an object is placed on the balance board, the force information from the X-axis, the Y-axis and the Z-axis can be collected and calculated to obtain the object's center-of-gravity position.
The three-dimensional center-of-gravity position measuring force plate as mentioned above features the modular design of pressure sensors. When an object is placed on the force plate, the force plate can capture the information of the object's center-of-gravity position. Said force plate can be applied to game machines, medical facilities, exercise measurements, and education equipment, etc.
However, the center-of-gravity measuring force plates on the market mostly use uniaxial or triaxial piezoelectric sensing elements to measure the position of center of gravity of an object. The piezoelectric sensing elements are placed in the four corners of the center-of-gravity measuring force plates, respectively, or placed at four beam columns of the center-of-gravity measuring force plates, respectively. The high-priced three-dimensional pressure sensor is currently imported. In a business point of view, it is therefore inconvenient to repair or replace the broken part once a sensor is damaged. Moreover, it is not suitable for home use and consequently the patient has to go to a hospital for examination.
Therefore, it is a common goal for businesses and developers to overcome the problems of a high-cost of electric force plate, inconvenient repair, and residential examination difficulties.